This invention relates to timepiece push-button structures and, more particularly, to an improvement over the timepiece push-button structure.
Wristwatches have become increasingly thinner and now employ a plurality of push-buttons to cope with a diversification in available functions. A problem that arises in this connection is how to design a structure for a switch that will operate reliably in a very limited amount of space. Although timepiece cases now available are already quite thin, a further reduction in thickness on the order of 0.1 to 0.2 millimeter would be a major advantage in terms of design which is restricted by so may factors. The effect of such a reduction in thickness would be of significance if it could be accomplished without sacrificing such properties as the water-proof property of a timepiece.
Push buttons generally employ a coil spring and exhibit resilience which derives from the spring. In order to impact a coil spring with resiliency of a sufficient magnitude, however, the spring must be of a certain length and is generally possessed of a complicated structure. Conventional arrangements that employ a leaf spring exhibit inadequate resilience, and a C-ring (a circular spring with a portion thereof cut away) must be provided to prevent the push-button from falling out of the case. When the number of such push-buttons installed in the case is increased, the spacing between adjacent push-buttons is diminished so that the assembly operation becomes a problem.